Most processed foods contain ingredients that had their DNA manipulated in a lab. The biotech industry insists these foods are completely safe to eat, but the activists at the rally were not buying that.

"We're targeting everybody," said Andrea Stander, the executive director of the group Rural Vermont, which advocates for a self-reliant food system and support for farmers who protect the earth. "We're targeting everybody because, I don't know about you, but I haven't met anybody yet who doesn't eat. And this is about people's food, and something that everybody does a couple of times a day, at least."

Stander is worried about genetically-modified organisms, or GMOs. Many crops, like corn and soybeans, had their DNA manipulated to boost yields for farmers or efficiency for food producers. Most food labels do not reflect that change.

Many remain deeply skeptical. Vt. state Sen. David Zuckerman, P-Chittenden County, told participants at the rally he is focused on ensuring a labeling law passes this session. "We don't want to be the guinea pigs, or continue to be guinea pigs. We want to have choice," said Zuckerman, who is also a farmer.

Like Vermont, Massachusetts, New Hampshire, New York, Rhode Island, are also considering labeling laws. The states of Maine and Connecticut have already passed laws requiring foods containing GMOs be labeled. However, the Vermont activists alleged those two states' laws are not really laws, because they don't actually take effect until a certain number of other states also pass labeling laws.

Zuckerman said he wants to see a GMO labeling bill that does not have a clause requiring other states to also pass laws. He acknowledged convincing some colleagues in the state Senate to take the leap will be a challenge.

Jim Harrison of the Vermont Grocers' Association told New England Cable News he fears lawsuits could come Vermont's way if the state requires food products sold here to be labeled differently than they are say, next door in New Hampshire. "To require labeling in Vermont and in Vermont only would be a huge mistake," Harrison said. "A federal, national, uniform system is the much-preferred way to go."

The demonstrators said they bet biotech firms would spend lots of money fighting a national requirement.

General Mills, the maker of Cheerios, said this month its original Cheerios will now be labeled as "Not Made With Genetically Modified Ingredients." The Associated Press noted that is not an official certification. The labels will also tell consumers that trace amounts of GMO ingredients could be present due to the manufacturing process, said Mike Siemienas, a company spokesman.

The change does not apply to any other Cheerios flavors, such as Apple Cinnamon Cheerios or Multi Grain Cheerios. The Minneapolis-based company said it has been manufacturing original Cheerios without GMOs for the past several weeks in response to consumer demand. It did not specify exactly when the boxes with the new labels would be on sale.

In 2013, the popular Vermont-based ice cream brand Ben & Jerry's pledged to go GMO-free with its ingredient sourcing by mid-2014. Some engineered ingredients existed in certain ice cream mix-ins, like the corn syrup in marshmallow swirls, Chris Miller, the social mission activism manager for Ben & Jerry's, told NECN in May of last year. "This is the right thing to do," Miller said. "We'll complete this conversion without having to raise the cost of a pint of ice cream or fundamentally impact the margins on the product."

Companies like the big seed-maker Monsanto have long argued the bio-engineering of crops has many benefits, including helping farmers use fewer pesticides and become more profitable by boosting crop yield. The company has a section of its website dedicated to defending itself from critics who worry about GMOs.

Some participants at the rally Thursday said they could take a bit of solace in knowing names like General Mills and Ben & Jerry's recognize the concern many consumers have about GMOs. Participants said they will not let up with their push, until laws in Vermont ensure foods are fully labeled.

"This is a really fundamental issue," Stander said. "More and more people are becoming aware of this issue; that there's a difference between genetically-engineered food and non-genetically engineered food, but we can't tell."

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